1. Field
The present disclosure relates to a multilayer piezoelectric device.
2. Disclosure of the Related Art
Japanese Patent Application Laid-Open No. 2003-250281 discloses a multilayer piezoelectric device used for an ink ejecting head provided in an ink-jet printer, for example. The multilayer piezoelectric device has a multilayer body in which piezoelectric layers are stacked, a common outer electrode, and a plurality of discrete outer electrodes. The multilayer body has a base and a plurality of driving parts and a pair of non-driving parts which extend from a principal surface of the base along the stacking direction of the piezoelectric layers. The multilayer body has first and second side faces opposing each other in a direction orthogonal to the stacking direction. The first side face forms one side face of the base, plurality of driving parts, and pair of non-driving parts, while the second side face forms the other side face of the base, plurality of driving parts, and pair of non-driving parts.
The plurality of driving parts and pair of non-driving parts align along a direction orthogonal to both of the stacking direction and the opposing direction of the first and second side faces, such that the plurality of driving parts is disposed between the pair of non-driving parts. In the plurality of driving parts, first and second inner electrodes alternately align along the stacking direction with the piezoelectric layer interposed therebetween. In the pair of non-driving parts, the piezoelectric layers and third inner electrodes alternately align along the stacking direction.
The first inner electrode has one end exposed to the first side face and the other end not exposed to the second side face. The second inner electrode has one end not exposed to the first side face and the other end exposed to the second side face. The third inner electrode has one end and the other end exposed to the first and second side faces, respectively.
The common outer electrode is arranged on the first side face of the multilayer body and connected to one end of the first inner electrode and one end of the third inner electrode. The discrete outer electrodes are arranged on the other side face of the plurality of driving parts and pair of non-driving parts and the other end of the second inner electrode and the other end of the third inner electrode. Therefore, the first and third inner electrodes have the same polarity. The polarity of the first and third inner electrodes differs from that of the second inner electrode.